Taking a dual look at lightning
The zigzagging fingers of blinding light and the booming thunderclap that follows are the familiar face of lightning, but the true nature of lightning, it turns out, is more than skin deep.
Scientists at the Laboratory, along with colleagues from Sandia National Laboratories, are using the FORTE satellite to continue looking deep into the mechanism of lightning, both optically and electrodynamically. They hope to one day provide a reliable statistical model for the bolts-from-the-blue and a host of other extreme weather conditions.
More than a dozen projects associated with the use of FORTE and other technologies to understand lightning are scheduled to be presented at a poster session today at the fall meeting of the American Geophysical Union. Included in the presentation are experiments that look at lightning's optical signals and radio frequency signals and a vast amount of related statistical data.
The primary mission of FORTE is to demonstrate advanced technologies for treaty verification and to take radio frequency and optical measurements of lightning, technologies that turn out to be ideal for detailed investigation of lightning. Inclined 70 degrees to the equator, FORTE's orbit takes the craft over some of the most lightning-prone places on Earth: South America, Africa and Southeast Asia, for example. Because it covers the whole globe and has a very large data-storage capability, FORTE provides an ideal platform to gather statistics on the characteristics of the radio-frequency emissions associated with lightning. To date, FORTE has received and recorded more than three million VHF signals associated with electrical storms.
"The thrust of all our research is to gather as much data as possible on lightning," said Diane Roussel-Dupre, FORTE flight operations manager and planner in Space Data Systems (NIS-3). "Our aim is to categorize the different kinds of lightning, collect a vast variety of statistics and correlate the Laboratory's FORTE and electric field change data with detection data from other sensors so that we can eventually better understand the mechanism that is responsible for lightning."
Using the optical and radio frequency detectors on FORTE in concert with ground-based detection and characterization technologies, scientists are building the ability to pinpoint the exact location of lightning strikes and correlate the electrodynamics and atmospheric conditions that are generally present with lightning.
"The ultimate utility of FORTE is in its ability to observe lightning by both optical and radio frequency means simultaneously," said Abe Jacobson, FORTE project leader. "By combining joint data from the Laboratory RF sensors and Sandia's fast photodiode and CCD imager sensors, we are able to tread new ground in the dual phenomonology of lightning seen from space.
"In other words," added Jacobson, "we're now not just one blind man looking at an elephant, but two partially-sighted men, looking at different ends of the elephant, acknowledging that the signals come from a related source and communicating that effectively."
In 1993, sensors aboard another Lab satellite, ALEXIS, discovered TIPPs, Trans-Ionospheric Pulse Pairs, extremely short pairs of radio pulses originating near storm centers. FORTE data has confirmed that the signal pairs correlate with lightning and that the second of the two signals is the result of signal reflection off the earth's surface. New work shows that along with ground-based data, TIPPs have proven to be an effective tool in determining a more specific location of a lightning strike, something not possible when looking at typical radio-frequency signals.
Expanding on technology and data already in hand from the National Lightning Detection Network, Laboratory researchers have developed their own ground-based network, called the Sferic Array. The Sferic Array very accurately measures the electric field changes near thunderstorms and is used to locate Compact Intercloud Discharges thought to be an indicator of the types and location of thunderstorms likely to produce lightning. The array currently consists of 11 detection stations in New Mexico, Nebraska, Texas and Florida.
"If we can associate the location of certain kinds of lightning or quantities of lightning to other extreme weather conditions like heavy hail and rain or tornadoes, then we're one step closer to a predictive weather model," said Roussel-Dupre. "The larger the data set the better. With enough data it also may be possible to look at the role of lightning in relation to global climate change."
--Kevin Roark
Laboratory Fellows Prize 2000 recipient
selected
Victor Klimov of Chemical Reactions, Kinetics and Dynamics (CST-6) has been selected to receive the Laboratory Fellows Prize 2000 for outstanding research in science.
The Fellow's Prize recognizes and stimulates high-quality published research in science and engineering having a significant impact on a particular field or discipline.
"The Fellow's Prize is highly competitive and about 25 Laboratory staff members have received the Fellows Prize since it was instituted in 1988," said Mikkel Johnson of Subatomic Physics (P-25), deputy coordinator of the Fellows and chair of this year's Fellows Prize committee.
"Dr. Klimov's nomination was enthusiastically and unanimously selected based on the technical excellence and impact of his research," said Johnson. "His ingeniously crafted, carefully designed experiments and his interpretation of them are important because they put on a firm scientific footing our understanding of behavior of 'quantum dot' systems, which are crucial to the design of highly efficient optical and optoelectronic devices, such as tunable lasers, photo-detectors and light emitting diodes.
"His contributions and those of past Fellow's Prize winners embody the high standards of science and engineering upon which the sustained greatness of our Laboratory so crucially depends," said Johnson.
"I am very happy and excited to be selected for this competitive award. It feels great that the importance of the subject, which I have been passionately studying, has been recognized by the Lab Fellows," said Klimov. "I also consider this recognition as an important milestone in the area of nano-materials research at the Lab. I started this activity about four years ago, mostly after hours and on weekends. Now, it has grown into a strong LDRD-funded research program that has gained wide recognition both inside and outside the Lab."
Nominations for the award are reviewed by a committee of Laboratory Fellows. Nominees must be full-time Lab employees; staff members of the Lab are eligible, however, Fellows and postdoctoral researchers are ineligible for consideration.
Klimov receives a $3,000 prize for being selected as the Fellows Prize winner. He is scheduled to deliver a Director's Colloquium on his research next month at the Laboratory.
Klimov joined the Laboratory in 1995. He received his master's and doctoral degrees in 1978 and 1981, respectively, from Moscow State University. From 1981 to 1993, Klimov held joint appointments at Moscow State University and Moscow Institute of Geodesy, first as an assistant professor and since 1987 as an associate professor. Between 1990 and 1995, Klimov had several visiting appointments as a visiting scientist (Humboldt University of Berlin) at Aachen Technical University in Aachen, Germany and a visiting professor (Madrid Autonomous University). In 1993, for his pioneering studies of semiconductor quantum dots he was awarded the highest Russian academic degree, Dr. of Sciences.
Klimov is a Fellow of the Alexander von Humboldt Foundation. He also received a Los Alamos Achievement Award in 1996 and 1997 and an International Science Foundation Award in 1992.
Klimov has written or co-authored more than 100 research articles, reviews and book chapters and delivered more than 30 invited talks at national international conferences and colloquia. His current research interests are in the field of photophysics of semiconductor quantum dots and conducting polymers and femtosecond optical instrumentation.
--Steve Sandoval
Study presents problem for geophysicists'
understanding of plate tectonics
Geophysicists may have to take another look at the mechanisms in plate tectonics due to a study by researchers from the Laboratory and the University of California, Riverside.
At issue is the discovery of microdiamonds within sedimentary crustal rocks in continental collision zones in Kazakhstan, Norway, China and Germany. The researchers are scheduled to discuss their findings today during the December meeting of the American Geophysical Union in San Francisco. Also, a paper detailing their work recently was submitted to the science journal Nature.
Based on geophysicists' current understanding of plate tectonics, microdiamonds, which range in size from a mere 1 micron (0.000039 of an inch) to 100 microns, aren't supposed to be found in any crustal rocks. With the exception of alluvial diamonds, which have been released from their original environment by erosion and deposited elsewhere, no diamonds of any size should be in crustal rocks. The Laboratory/UC Riverside research team believes that the microdiamonds formed deep inside Earth's mantle.
"Most geophysicists disputed and ultimately dismissed the microdiamonds' existence when they first were discovered in Kazakhstan in the mid-1970s," said Kristin Bennett of the Los Alamos Neutron Science Center (LANSCE), where some of the research was performed. "However, other geophysicists have since confirmed the presence of microdiamonds in Kazakhstan and other places around the world. This is a very hot topic in geophysics right now because it could change our understanding of plate tectonics."
In plate tectonics, when two plates of Earth's outer shell collide, the heavier rock gets pushed down (subducted) back into the mantle, the only place where pressures and temperatures are high enough to form diamonds, explained study project leader Larissa Dobrzhinetskaya of UC Riverside. Volcanic eruptions later force diamonds up through the mantle and crust via narrow conduits called kimberlitic pipes.
"The microdiamonds were discovered within crustal rocks, which until recently was considered not possible because the laws of physics hold that they are too light to be subducted," she said.
To explain this geophysical enigma, Dobrzhinetskaya, UC Riverside colleague Harry Green and Laboratory colleagues Terrence Mitchell and Robert Dickerson, both of the Center for Materials Science (MST-CMS), studied the mineral inclusions found inside microdiamonds obtained from Kazakhstan. The inclusions serve as an environmental record of the conditions under which the microdiamonds formed.
Their analyses revealed that the microdiamonds have an imperfect, skeletal crystalline structure, much like the shape of a gypsum desert rose commonly found in the Southwest. Conversely, typical diamonds have perfect crystalline structures.
"Their imperfect structure suggests that they most likely formed in an impure environment, meaning drops of fluid oversaturated with carbon and water eventually turned into diamonds in an environment laden with other minerals," Dobrzhinetskaya said. Such minerals included several types of silicates, carbonates and oxides, some of which are found only in crustal rock, she noted.
"The presence of these minerals suggests that continental collisions must have forced at least some of Earth's crustal rock down a subduction zone, where it somehow mixed with the mantle materials, then rose back to the surface over tens of millions of years, which is considered fast in terms of tectonic processes, " she said.
The researchers postulate that the mineral inclusions -- and thus the diamonds -- were formed very deep inside the mantle.
"If our future analyses of the mineral inclusions' chemical compositions and crystalline structures confirm this," said Dobrzhinetskaya, "then the theory of plate tectonics will need to be reworked to account for how some crustal rocks managed to make a round trip from Earth's surface deep into the mantle and back, and under what circumstances."
The Laboratory's Center for Materials Science, Institute of Geophysics and Planetary Physics and Los Alamos Neutron Science Center, and UC Riverside collaborated on the project, with support from the Lab's Science and Technology Base (STB) Programs Office.
--Ternel N. Martinez
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The Laboratory and Department of Energy announce the first of an ongoing series of Environmental Restoration (ER) Project information "availability sessions" for local governments, tribes and the public, beginning with a meeting from 4 to 8 p.m. Thursday. The first session will be held at the Laboratory's Community Reading Room, located at 1619 Central Avenue, Los Alamos. "The purpose of these meetings is to discuss current ER Project issues with governments, tribes and the public in real time. We plan to hold these sessions on an ongoing basis, at different locations throughout Northern New Mexico," said Julie Canepa, manager of the ER Project. "We used to host these meetings several years ago. It gave members of the public a chance to sit down with us in an informal setting and talk about ER project issues and events of interest to them." Times and locations of future meetings will be announced on the Laboratory's Web site, or can be obtained by calling Carmen M. Rodriguez with the ER Project Communications and Outreach Team at 5-6770 or 1-800-508-4400. You also may send e-mail to carmenr@lanl.gov. --James E. Rickman |
Newest Bernd T. Matthias Scholar named
Richard Hoagland is the newest Bernd T. Matthias Scholar in the Center for Materials Science (MST-CMS) at the Laboratory.
Hoagland, a professor in the mechanical and materials engineering department at Washington State University, is an internationally recognized expert in computer simulation of atomic processes in materials, composite materials and the relationship between microstructure and mechanical properties of materials.
Former Laboratory Director Donald Kerr, in 1984, instituted a program to support limited-term appointments for outstanding materials scientists to visit the Laboratory to conduct materials research and development. This program became the Bernd T. Matthias Visiting Scholar at CMS.
The focus of the Bernd T. Matthias program has been materials science, according to Terry Mitchell of MST-CMS.
Matthias, a condensed matter physicist, worked for the University of California, San Diego, and Bell Labs. Matthias came to Los Alamos summers between 1960 and 1980. "He was very influential here in terms of stimulating people to do all kinds of research," said Mitchell.
"Matthias was the first external Fellow of Los Alamos," said Mitchell.
Researchers at the Center for Materials Science select the Matthias Scholar using input from other researchers across the Lab who interact with CMS. Candidate names and résumés are submitted to CMS leadership.
Approximately a year before an appointment is made, CMS leadership and staff review the candidates and make a selection. They then forward the name to the Laboratory director for approval. Each appointment is designed to fit the specific needs and circumstances of the person selected.
Hoagland joined Washington State University in 1987 and was chairman of the Materials Science Program at Washington State from 1990 to 1993. He was an associate then full professor in the department of metallurgical engineering at Ohio State University from 1980 through 1986.
He also spent one year at Vanderbilt University, and for 10 years was principal research scientist at Battelle Columbus Laboratories in Columbus, Ohio. From 1962 to 1969, Hoagland was a research scientist at Battelle Northwest Laboratories in Richland, Wash.
He has a bachelor's degree in metallurgical engineering from Colorado School of Mines and a master's degree in materials science from Washington State. He earned a doctoral of philosophy in metallurgical engineering from Ohio State in 1973.
Hoagland is a Fellow of the American Society of Metals and a member of the American Society of Metals, the Metallurgical Society of the American Institute of Metallurgical Engineering, (now the Professional Metallurgical Society), Sigma Xi, the Materials Research Society and the American Physical Society.
Previous Bernd Matthias Scholars are
--Steve Sandoval
Maximum contributions to 403(b) plans to increase in 2000
Effective January 2000, the Tax Reform Act limit on contributions to tax-deferred 403(b) plans will increase to $10,500 from $10,000. For Laboratory employees who will be eligible to contribute the full $10,500 and who want to contribute a level amount over 26 paychecks to either their University of California investments or to Fidelity Investments, the increase will allow a maximum contribution of $403.84 per paycheck.
In March 2000, participants in the 403(b) plan will receive statements notifying them of the amount of their maximum annual contribution for the year. In the meantime, however, employees who wish to change their 403(b) contribution amount for January can do so now. Employees are reminded that in general, they can change their 403(b) contribution at any time. However, changes do need to be made soon if the employee wants the new contribution level to go into effect by Jan. 13. Employees can change the level of their contribution in three ways:
The first two options require that the employee establish a personal identification number, or PIN. Employees can set up a PIN or ask questions about the 403(b) plan, by calling the Benefits office at 7-1806 or by sending e-mail to benefits@lanl.gov. The deadline for making changes for the Jan. 13 paycheck, using any of these methods, is 5 p.m. PST Dec. 21.
--David Lyons
ARAMARK to serve
New Mexican holiday meal today
ARAMARK Corp. is serving its traditional New Mexican holiday meal today in the Otowi Building Cafeteria at Technical Area 3 and cafeterias at TA-55 and the Los Alamos Neutron Science Center (LANSCE) at TA-53.
The meal costs $7.25 and includes red chile beef or green chile chicken enchiladas, tamales, rice, ranchero beans, posole, sopapillas and natillas. The cost also includes a 22-ounce fountain drink.
If the traditional meal doesn't suit your fancy, employees also can purchase a prime rib dinner consisting of roasted prime rib au jus, rosemary new potatoes, braised vegetable medley and a dinner roll.
Pre-packaged sandwiches also are available for purchase and the salad and soup bar will be open.
The cafeterias, which are run by ARAMARK Corp., are open for lunch from 11 a.m. to 1:30 p.m.
ARAMARK Corp. catering trucks will serve the holiday meal on Thursday, Dec. 16.
For more information, go to http://www.lanl.gov/labview/services/CafeteriaMenu/holiday.htm online or call 7-3591.
--Steve Sandoval
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Forum examines professionalism in the workplace Laboratory Fellow Jerry Wilhelmy of Nuclear and Radiochemistry (CST-11) addresses the audience during a forum on security Tuesday hosted by the Los Alamos section of the Institute of Electrical and Electronics Engineers. The event, "Professionalism, Security and Civil Rights" was scheduled for the Physics Building Auditorium but was moved to the Otowi Cafeteria side dining rooms. The focus of the forum was to examine professionalism in the workplace and workers civil rights and responsibilities in an increasingly security-tightened environment. Photo by LeRoy N. Sanchez |
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